2016 day2 part1

3 files changed, 52 insertions, 3 deletions

diff --git a/src/2016/day2/aoc.cpp b/src/2016/day2/aoc.cpp
index 55f4247..3b5b28b 100644
--- a/src/2016/day2/aoc.cpp
+++ b/src/2016/day2/aoc.cpp
@@ -2,4 +2,17 @@
 
 namespace aoc2016 {
 
+int day2(line_view file) {
+  int d{0};
+  int l{5};
+  keybad pad;
+  per_line(file, [&d, &l, &pad](line_view lv) {
+    l = pad.touch(l, lv.line);
+    // printf("%d\n", l);
+    d = d * 10 + l;
+    return true;
+  });
+  return d;
 }
+
+} // namespace aoc2016
diff --git a/src/2016/day2/aoc.h b/src/2016/day2/aoc.h
index 4239dbc..2b444cd 100644
--- a/src/2016/day2/aoc.h
+++ b/src/2016/day2/aoc.h
@@ -1,7 +1,43 @@
 #pragma once
-
 #include "common.h"
 
 namespace aoc2016 {
 
-}
+struct keybad {
+  enum move {
+    up,
+    right,
+    down,
+    left,
+  };
+
+  int keys[9][4] = {
+      {1, 2, 4, 1}, {2, 3, 5, 1}, {3, 3, 6, 2}, {1, 5, 7, 4}, {2, 6, 8, 4},
+      {3, 6, 9, 5}, {4, 8, 7, 7}, {5, 9, 8, 7}, {6, 9, 9, 8},
+  };
+
+  int touch(int i, char c) {
+    static int az[] = {
+        INT_MAX, INT_MAX, INT_MAX,
+        2,                                                                // D
+        INT_MAX, INT_MAX, INT_MAX, INT_MAX, INT_MAX, INT_MAX, INT_MAX, 3, // L
+        INT_MAX, INT_MAX, INT_MAX, INT_MAX, INT_MAX,
+        1,                   // R
+        INT_MAX, INT_MAX, 0, // U
+        INT_MAX, INT_MAX, INT_MAX, INT_MAX, INT_MAX,
+    };
+    return keys[i - 1][az[c - 'A']];
+  }
+
+  int touch(int i, const char* p) {
+    while (*p >= 'A' && *p <= 'Z') {
+      i = touch(i, *p);
+      p++;
+    }
+    return i;
+  }
+};
+
+int day2(line_view);
+
+} // namespace aoc2016
diff --git a/src/2020/day2/aoc.h b/src/2020/day2/aoc.h
index 4239dbc..0a640bb 100644
--- a/src/2020/day2/aoc.h
+++ b/src/2020/day2/aoc.h
@@ -2,6 +2,6 @@
 
 #include "common.h"
 
-namespace aoc2016 {
+namespace aoc2020 {
 
 }